<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2023 Workiva-->
<!--r:6517acae-4533-4b41-af86-61933115c4be,g:534dcbed-da35-4848-959c-5965c7debeab-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:lh="http://www.labcorp.com/20230331" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.labcorp.com/20230331">
  <xs:import namespace="http://fasb.org/srt/2022" schemaLocation="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2022" schemaLocation="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd"/>
  <xs:import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/country/2022" schemaLocation="https://xbrl.sec.gov/country/2022/country-2022.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2022" schemaLocation="https://xbrl.sec.gov/dei/2022/dei-2022.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="lh-20230331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="lh-20230331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="lh-20230331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="lh-20230331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="CoverPage" roleURI="http://www.labcorp.com/role/CoverPage">
        <link:definition>0000001 - Document - Cover Page</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDBALANCESHEETSUnaudited" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUnaudited">
        <link:definition>0000002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDBALANCESHEETSUnauditedParentheticals" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUnauditedParentheticals">
        <link:definition>0000003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSUnaudited" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSUnaudited">
        <link:definition>0000004 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEEARNINGSUnaudited" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEEARNINGSUnaudited">
        <link:definition>0000005 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITYUnaudited" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITYUnaudited">
        <link:definition>0000006 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StatementofCashFlowsStatement" roleURI="http://www.labcorp.com/role/StatementofCashFlowsStatement">
        <link:definition>0000007 - Statement - Statement of Cash Flows (Statement)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited" roleURI="http://www.labcorp.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited">
        <link:definition>0000008 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StatementofCashFlowsSupplementalDisclosures" roleURI="http://www.labcorp.com/role/StatementofCashFlowsSupplementalDisclosures">
        <link:definition>0000009 - Statement - Statement of Cash Flows, Supplemental Disclosures</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BASISOFFINANCIALSTATEMENTPRESENTATIONRestatedFinancialStatements" roleURI="http://www.labcorp.com/role/BASISOFFINANCIALSTATEMENTPRESENTATIONRestatedFinancialStatements">
        <link:definition>0000010 - Statement - BASIS OF FINANCIAL STATEMENT PRESENTATION Restated Financial Statements</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUPPLEMENTALCASHFLOWINFORMATIONDescriptionInformation" roleURI="http://www.labcorp.com/role/SUPPLEMENTALCASHFLOWINFORMATIONDescriptionInformation">
        <link:definition>0000011 - Statement - SUPPLEMENTAL CASH FLOW INFORMATION Description Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BASISOFFINANCIALSTATEMENTPRESENTATION" roleURI="http://www.labcorp.com/role/BASISOFFINANCIALSTATEMENTPRESENTATION">
        <link:definition>0000012 - Disclosure - BASIS OF FINANCIAL STATEMENT PRESENTATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHARE" roleURI="http://www.labcorp.com/role/EARNINGSPERSHARE">
        <link:definition>0000013 - Disclosure - EARNINGS PER SHARE</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NONCONTROLLINGINTERESTPUTS" roleURI="http://www.labcorp.com/role/NONCONTROLLINGINTERESTPUTS">
        <link:definition>0000014 - Disclosure - NONCONTROLLING INTEREST PUTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDINTANGIBLEASSETS" roleURI="http://www.labcorp.com/role/GOODWILLANDINTANGIBLEASSETS">
        <link:definition>0000015 - Disclosure - GOODWILL AND INTANGIBLE ASSETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBT" roleURI="http://www.labcorp.com/role/DEBT">
        <link:definition>0000016 - Disclosure - DEBT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITY" roleURI="http://www.labcorp.com/role/PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITY">
        <link:definition>0000017 - Disclosure - PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMITMENTSANDCONTINGENCIES" roleURI="http://www.labcorp.com/role/COMMITMENTSANDCONTINGENCIES">
        <link:definition>0000018 - Disclosure - COMMITMENTS AND CONTINGENCIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEMEASUREMENTS" roleURI="http://www.labcorp.com/role/FAIRVALUEMEASUREMENTS">
        <link:definition>0000019 - Disclosure - FAIR VALUE MEASUREMENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSACQUISITIONS" roleURI="http://www.labcorp.com/role/BUSINESSACQUISITIONS">
        <link:definition>0000020 - Disclosure - BUSINESS ACQUISITIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSSEGMENTINFORMATIONNotes" roleURI="http://www.labcorp.com/role/BUSINESSSEGMENTINFORMATIONNotes">
        <link:definition>0000021 - Disclosure - BUSINESS SEGMENT INFORMATION (Notes)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSSEGMENTINFORMATIONBusinessSegmentinformationNotes" roleURI="http://www.labcorp.com/role/BUSINESSSEGMENTINFORMATIONBusinessSegmentinformationNotes">
        <link:definition>0000022 - Disclosure - BUSINESS SEGMENT INFORMATION Business Segment information (Notes)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUENotes" roleURI="http://www.labcorp.com/role/REVENUENotes">
        <link:definition>0000023 - Disclosure - REVENUE (Notes)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEvents" roleURI="http://www.labcorp.com/role/SubsequentEvents">
        <link:definition>0000024 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IntangibleAssetsGoodwillandOtherPolicies" roleURI="http://www.labcorp.com/role/IntangibleAssetsGoodwillandOtherPolicies">
        <link:definition>0000025 - Disclosure - Intangible Assets, Goodwill and Other (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractwithCustomerPolicies" roleURI="http://www.labcorp.com/role/RevenuefromContractwithCustomerPolicies">
        <link:definition>0000026 - Disclosure - Revenue from Contract with Customer (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHARETables" roleURI="http://www.labcorp.com/role/EARNINGSPERSHARETables">
        <link:definition>0000027 - Disclosure - EARNINGS PER SHARE (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDINTANGIBLEASSETSTables" roleURI="http://www.labcorp.com/role/GOODWILLANDINTANGIBLEASSETSTables">
        <link:definition>0000028 - Disclosure - GOODWILL AND INTANGIBLE ASSETS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEMEASUREMENTSTables" roleURI="http://www.labcorp.com/role/FAIRVALUEMEASUREMENTSTables">
        <link:definition>0000029 - Disclosure - FAIR VALUE MEASUREMENTS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSSEGMENTINFORMATIONTables" roleURI="http://www.labcorp.com/role/BUSINESSSEGMENTINFORMATIONTables">
        <link:definition>0000030 - Disclosure - BUSINESS SEGMENT INFORMATION (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUETables" roleURI="http://www.labcorp.com/role/REVENUETables">
        <link:definition>0000031 - Disclosure - REVENUE (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEventsTables" roleURI="http://www.labcorp.com/role/SubsequentEventsTables">
        <link:definition>0000032 - Disclosure - Subsequent Events (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BASISOFFINANCIALSTATEMENTPRESENTATIONDetails" roleURI="http://www.labcorp.com/role/BASISOFFINANCIALSTATEMENTPRESENTATIONDetails">
        <link:definition>0000033 - Disclosure - BASIS OF FINANCIAL STATEMENT PRESENTATION (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHAREReconciliationofBasicEarningsPerSharetoDilutedEarningsPerShareDetails" roleURI="http://www.labcorp.com/role/EARNINGSPERSHAREReconciliationofBasicEarningsPerSharetoDilutedEarningsPerShareDetails">
        <link:definition>0000034 - Disclosure - EARNINGS PER SHARE (Reconciliation of Basic Earnings Per Share to Diluted Earnings Per Share) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHAREPotentialcommonsharesnotincludedincomputationofdilutedearningspershareDetails" roleURI="http://www.labcorp.com/role/EARNINGSPERSHAREPotentialcommonsharesnotincludedincomputationofdilutedearningspershareDetails">
        <link:definition>0000035 - Disclosure - EARNINGS PER SHARE (Potential common shares not included in computation of diluted earnings per share) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NONCONTROLLINGINTERESTPUTSDetails" roleURI="http://www.labcorp.com/role/NONCONTROLLINGINTERESTPUTSDetails">
        <link:definition>0000036 - Disclosure - NONCONTROLLING INTEREST PUTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDINTANGIBLEASSETSChangesinCarryingAmountofGoodwillDetails" roleURI="http://www.labcorp.com/role/GOODWILLANDINTANGIBLEASSETSChangesinCarryingAmountofGoodwillDetails">
        <link:definition>0000037 - Disclosure - GOODWILL AND INTANGIBLE ASSETS (Changes in Carrying Amount of Goodwill) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDINTANGIBLEASSETSComponentsofidentifiableintangibleassetsDetails" roleURI="http://www.labcorp.com/role/GOODWILLANDINTANGIBLEASSETSComponentsofidentifiableintangibleassetsDetails">
        <link:definition>0000038 - Disclosure - GOODWILL AND INTANGIBLE ASSETS (Components of identifiable intangible assets) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDINTANGIBLEASSETSDetails" roleURI="http://www.labcorp.com/role/GOODWILLANDINTANGIBLEASSETSDetails">
        <link:definition>0000039 - Disclosure - GOODWILL AND INTANGIBLE ASSETS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTShorttermborrowingsandcurrentportionoflongtermdebtTableDetails" roleURI="http://www.labcorp.com/role/DEBTShorttermborrowingsandcurrentportionoflongtermdebtTableDetails">
        <link:definition>0000040 - Disclosure - DEBT (Short-term borrowings and current portion of long-term debt) (Table) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTLongtermdebtDetails" roleURI="http://www.labcorp.com/role/DEBTLongtermdebtDetails">
        <link:definition>0000041 - Disclosure - DEBT (Long-term debt) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTSeniorNotesDetails" roleURI="http://www.labcorp.com/role/DEBTSeniorNotesDetails">
        <link:definition>0000042 - Disclosure - DEBT (Senior Notes) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTCreditFacilitiesDetails" roleURI="http://www.labcorp.com/role/DEBTCreditFacilitiesDetails">
        <link:definition>0000043 - Disclosure - DEBT (Credit Facilities) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYDetails" roleURI="http://www.labcorp.com/role/PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYDetails">
        <link:definition>0000044 - Disclosure - PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYPREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYAccumulatedOtherComprehensiveEarningsDetails" roleURI="http://www.labcorp.com/role/PREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYPREFERREDSTOCKANDCOMMONSHAREHOLDERSEQUITYAccumulatedOtherComprehensiveEarningsDetails">
        <link:definition>0000045 - Disclosure - PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY - Accumulated Other Comprehensive Earnings (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMITMENTSANDCONTINGENCIESDetails" roleURI="http://www.labcorp.com/role/COMMITMENTSANDCONTINGENCIESDetails">
        <link:definition>0000046 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FAIRVALUEMEASUREMENTSDetails" roleURI="http://www.labcorp.com/role/FAIRVALUEMEASUREMENTSDetails">
        <link:definition>0000047 - Disclosure - FAIR VALUE MEASUREMENTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSACQUISITIONSDetails" roleURI="http://www.labcorp.com/role/BUSINESSACQUISITIONSDetails">
        <link:definition>0000048 - Disclosure - BUSINESS ACQUISITIONS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSSEGMENTINFORMATIONBusinessSegmentInformationDetails" roleURI="http://www.labcorp.com/role/BUSINESSSEGMENTINFORMATIONBusinessSegmentInformationDetails">
        <link:definition>0000049 - Disclosure - BUSINESS SEGMENT INFORMATION Business Segment Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUEDetails" roleURI="http://www.labcorp.com/role/REVENUEDetails">
        <link:definition>0000050 - Disclosure - REVENUE (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUEDisaggregatedRevenueTableDetails" roleURI="http://www.labcorp.com/role/REVENUEDisaggregatedRevenueTableDetails">
        <link:definition>0000051 - Disclosure - REVENUE Disaggregated Revenue Table (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEventsDetails" roleURI="http://www.labcorp.com/role/SubsequentEventsDetails">
        <link:definition>0000052 - Disclosure - Subsequent Events (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="lh_InProcessRAAndMediaMember" abstract="true" name="InProcessRAAndMediaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_ThirdpartyMember" abstract="true" name="ThirdpartyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_PerShareAmountAbstract" abstract="true" name="PerShareAmountAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_DrugDevelopmentMember" abstract="true" name="DrugDevelopmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_NetRestructuringAndOtherSpecialCharges" abstract="false" name="NetRestructuringAndOtherSpecialCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_A2.30seniornotesdue2024" abstract="false" name="A2.30seniornotesdue2024" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_SeniorNotesDue2031Member" abstract="true" name="SeniorNotesDue2031Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_Contingentconsiderationadjustment" abstract="false" name="Contingentconsiderationadjustment" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_MedicareandMedicaidMember" abstract="true" name="MedicareandMedicaidMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_Seniornotesdue2027Member" abstract="true" name="Seniornotesdue2027Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_NumberofMeasurementFundsAvailableForParticipantElection" abstract="false" name="NumberofMeasurementFundsAvailableForParticipantElection" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="lh_CashPaidDuringPeriodForAbstract" abstract="true" name="CashPaidDuringPeriodForAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CommonSharesIssuedRollforwardAbstract" abstract="true" name="CommonSharesIssuedRollforwardAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CovanceDrugDevelopmentMember" abstract="true" name="CovanceDrugDevelopmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SwapTypeAxis" abstract="true" name="SwapTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lh_OtheracquireesMember" abstract="true" name="OtheracquireesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_Longtermdebtissuancecosts" abstract="false" name="Longtermdebtissuancecosts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ScheduleOfOtherIntangibleAssetsByMajorClassAxis" abstract="true" name="ScheduleOfOtherIntangibleAssetsByMajorClassAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lh_A400SeniorNotesDue2023" abstract="false" name="A400SeniorNotesDue2023" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_A360SeniorNotesDue2027" abstract="false" name="A360SeniorNotesDue2027" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_DiagnosticsMember" abstract="true" name="DiagnosticsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A360SeniorNotesDue2025" abstract="false" name="A360SeniorNotesDue2025" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_A2018SwapAgreementsMember" abstract="true" name="A2018SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SeniorNotesDue2022Member" abstract="true" name="SeniorNotesDue2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SeniorNotesFairValue" abstract="false" name="SeniorNotesFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_FairValueLiabilitiesMeasuredOnRecurringBasisNoncontrollingInterestPuts" abstract="false" name="FairValueLiabilitiesMeasuredOnRecurringBasisNoncontrollingInterestPuts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ScheduleOfOtherIntangibleAssetsByMajorClassDomain" abstract="true" name="ScheduleOfOtherIntangibleAssetsByMajorClassDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A2022SwapAgreementsMember" abstract="true" name="A2022SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_UnbilledContractsReceivableMember" abstract="true" name="UnbilledContractsReceivableMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A325SeniorNotesDue2024" abstract="false" name="A325SeniorNotesDue2024" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ForeignCurrencyTranslationAdjustmentsMember" abstract="true" name="ForeignCurrencyTranslationAdjustmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A155SeniorNotesDue2026" abstract="false" name="A155SeniorNotesDue2026" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_Percentofremainingperformanceobligationsrecognizedasrevenueinnextyear" abstract="false" name="Percentofremainingperformanceobligationsrecognizedasrevenueinnextyear" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lh_IncreaseDecreaseinUnbilledContractReceivable" abstract="false" name="IncreaseDecreaseinUnbilledContractReceivable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_UnbilledServicesAllowanceforCreditLoss" abstract="false" name="UnbilledServicesAllowanceforCreditLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_CommonsStockIssuedDuringPeriodSharesEmployeeStockPlans" abstract="false" name="CommonsStockIssuedDuringPeriodSharesEmployeeStockPlans" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="lh_CommonSharesHeldInTreasuryRollforwardAbstract" abstract="true" name="CommonSharesHeldInTreasuryRollforwardAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_OthercountriesMember" abstract="true" name="OthercountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_NetRestructuringCharges" abstract="false" name="NetRestructuringCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_SegmentReconciliationofOperatingIncometoConsolidatedAbstract" abstract="true" name="SegmentReconciliationofOperatingIncometoConsolidatedAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_AccumulatedOtherComprehensiveEarningsRollForward" abstract="true" name="AccumulatedOtherComprehensiveEarningsRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_FairValueLiabilitiesMeasuredOnRecurringBasisDeferredCompensationLiability" abstract="false" name="FairValueLiabilitiesMeasuredOnRecurringBasisDeferredCompensationLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_CurrentDebtExcludingFinanceLeaseLiability" abstract="false" name="CurrentDebtExcludingFinanceLeaseLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_PercentofRevenueContributed" abstract="false" name="PercentofRevenueContributed" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lh_CreditFacilityMaximumLettersofCredit" abstract="false" name="CreditFacilityMaximumLettersofCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_NoteReceivableAllowanceforCreditLoss" abstract="false" name="NoteReceivableAllowanceforCreditLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ThreeMonthLIBOR" abstract="false" name="ThreeMonthLIBOR" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lh_OtherFinancingCashFlows" abstract="false" name="OtherFinancingCashFlows" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_PatentsLicensesAndTechnologyMember" abstract="true" name="PatentsLicensesAndTechnologyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_InterestPaidInCash" abstract="false" name="InterestPaidInCash" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_IncreaseInCapitalExpendituresIncurredButNotYetPaid" abstract="false" name="IncreaseInCapitalExpendituresIncurredButNotYetPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_AllowanceforCreditLoss" abstract="false" name="AllowanceforCreditLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_IncomeAbstract" abstract="true" name="IncomeAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CommonSharesOutstandingRollforwardAbstract" abstract="true" name="CommonSharesOutstandingRollforwardAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_SeniorNotesDue2024Member" abstract="true" name="SeniorNotesDue2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_IncomeLossfromContinuingOperationsBeforeIncomeTaxesandNoncontrollingInterest" abstract="false" name="IncomeLossfromContinuingOperationsBeforeIncomeTaxesandNoncontrollingInterest" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_LongTermContractsDurationMaximum" abstract="false" name="LongTermContractsDurationMaximum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="lh_ClientMember" abstract="true" name="ClientMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A270SeniorNotesDue2031" abstract="false" name="A270SeniorNotesDue2031" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_CashFlowLocationDomain" abstract="true" name="CashFlowLocationDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_AllowanceforCreditLossWriteOff" abstract="false" name="AllowanceforCreditLossWriteOff" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_A2.95seniornotesdue2029" abstract="false" name="A2.95seniornotesdue2029" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_NoncontrollingInterestPutsAbstract" abstract="true" name="NoncontrollingInterestPutsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CurrentExpectedCreditLossesOpeningBalanceSheetImpactonRetainedEarnings" abstract="false" name="CurrentExpectedCreditLossesOpeningBalanceSheetImpactonRetainedEarnings" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_DepreciationAndAmortizationOfLeasedAssets" abstract="false" name="DepreciationAndAmortizationOfLeasedAssets" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_A470SeniorNotesDue2045" abstract="false" name="A470SeniorNotesDue2045" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_Issuanceofcommonstockunderemployeeplans" abstract="false" name="Issuanceofcommonstockunderemployeeplans" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_LongTermContractsDurationMinimum" abstract="false" name="LongTermContractsDurationMinimum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="lh_CashFlowLocationAxis" abstract="true" name="CashFlowLocationAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lh_Shorttermdebtissuancecosts" abstract="false" name="Shorttermdebtissuancecosts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_NoncontrollingInterestMezzanineEquity" abstract="false" name="NoncontrollingInterestMezzanineEquity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_SwapTypeDomain" abstract="true" name="SwapTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_OutstandingStockRepurchaseAuthorizationAbstract" abstract="true" name="OutstandingStockRepurchaseAuthorizationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_SharesAbstract" abstract="true" name="SharesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CreditFacilityMaximumSwingLineBorrowings" abstract="false" name="CreditFacilityMaximumSwingLineBorrowings" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_BiopharmaceuticalandmedicaldevicecompaniesMember" abstract="true" name="BiopharmaceuticalandmedicaldevicecompaniesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_CostMethodInvestmentsMaximumOwnershipPercentage" abstract="false" name="CostMethodInvestmentsMaximumOwnershipPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lh_DeferredIncomeTaxesAndOtherTaxLiabilities" abstract="false" name="DeferredIncomeTaxesAndOtherTaxLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_LabCorpDiagnosticsMember" abstract="true" name="LabCorpDiagnosticsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_NetProceedsFromIssuanceOfStockToEmployees" abstract="false" name="NetProceedsFromIssuanceOfStockToEmployees" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_CreditFacilityOptiontoIncrease" abstract="false" name="CreditFacilityOptiontoIncrease" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ChangesInCommonSharesIssuedAndHeldInTreasuryTableTextBlock" abstract="false" name="ChangesInCommonSharesIssuedAndHeldInTreasuryTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
</xs:schema>
